Fluid sampling valve

ABSTRACT

A sampling valve to be used in the system wherein fluid samples are to be selectively taken from a plurality of sources and fed to a common monitoring device or the like is provided with a valve block having separate parallel bores to be connected to the sources, a common independent exhaust bore to receive continuous flow from all of the source bores, and a corresponding plurality of sample passages for tapping each of the source bores between their inlets and the common exhaust bore. The system may be balanced and calibrated with set screw restrictors for each of the source bores. A common rotary cam shaft operates bracket mounted L-shaped pivoting levers for actuating corresponding numbers of switches and diaphragm type valves in fluid series between the sample passages communicating with the source bores and a single sample outlet.

United @tatee Patettt [191 Lude'wig, .11.

[ 51 Sept. 11, 1973 FLUKE) SAMPLING VALVE [75] inventor: Frederick A. Ludewig, Jan, Ballston Spa, NY.

[73] Assignee: Environment/One Corporation,

Schenectady, NY.

[22] Filed: Feb. 8, 1971 [211 App]. No.: 113,256

[52] 11.8. C1 711/4215 R, 137/625.11, 251/331 [51] int. Cl. G01n 1/26 [58] Field of Search 73/421 R, 422 R; 137/625.18, 625.11, 608; 251/331 [56] References Cited UNITED STATES PATENTS 2,781,780 2/1957 Zahradka 137/608 3,613,729 10/1971 Dora 251/331 2,895,497 7/1959 Jonesm. 251/331 2,965,134 12/1960 Pouppirt, Jr. 73/422 R X 3,464,448 9/1969 Schmitz 137/625.l8

2 -V-2M SOURCE Primary Examiner-S. Clement Swisher AttorneyCharles W. Helzer [57] ABSTRACT A sampling valve to be used in the system wherein fluid samples are to be selectively taken from a plurality of sources and fed to a common monitoring device or the like is provided with a valve block having separate parallel bores to be connected to the sources, a common independent exhaust bore to receive continuous flow from all of the source bores, and a corresponding plurality of sample passages for tapping each of the source bores between their inlets and the common exhaust bore. The system may be balanced and calibrated with set screw restrictors for each of the source bores. A common rotary cam shaft operates bracket mounted L-shaped pivoting levers for actuating corresponding numbers of switches and diaphragm type valves in fluid series between the sample passages communicating with the source bores and a single sample outlet.

20 Claims, 3 Drawing Figures EXHAUST Patented Sept. 11, 1973 3,757,583

2 Sheets-Sheet 1 6 2 V SOURCE Q E PUMP SOURCE PUMP 2 a 9 -5 l/vlz 1| l7 EXHAUST INVENTOR FREDERICK A. LUDEWIG JR,

ATTORNEYS FLUID SAMPLING VALVE CROSS-REFERENCE TO RELATED APPLICATION The sampling valve of the present invention is the sampling valve broadly shown in the system's disclosure of applicants U.S. Pat. No. 3,678,487, issued July 18, 1972, with common assignee, filed on even date with the present application, and entitled Multi-Zone Incipient Or Actual Fire and/or Dangerous Gas Detec tion System with co-inventor Frank W. Van Luik.

The disclosure of applicants copending aboveidentified application is incorporated herein in its entirety by reference the same as if all of the disclosure material therein were contained in the present application.

BACKGROUND OF THE INVENTION There are many systems in which it is desirable to selectively draw a fluid sample from a plurality of sources and feed it to a common monitoring instrument or the like. A plurality of poppet valves are employed in the patent to Pouppirt, .lr., U.S. Pat. No. 2,721 ,578, issued Oct. 25, I955 for this general purpose and to be actuated by a driven cam. However, this patent employs a system wherein the rotatable shaft must be sealed with respect to the valve chambers, which produces problems of leakage in either direction, considerable inaccuracy is present in that flow is not constant through the various lines between the sources and valve, and separate cams must be employed for the electric control switches and for the valves. Further, the construction is quite complicated which would result in increased manufacturing cost and maintenance cost.

A system such as that employed in the Dunham et al patent, U.S. Pat. No. 3,209,343, does provide constant flow from each of the sources, but there would appear to be considerable structural difficulties in providing the rotatable selective valve that is only generally shown, particularly with respect to sealing and dwell time.

A diaphragm type sampling valve is shown in the patent to McNown, U.S. Pat. No. 3,425,446, but considerable sealing difi'iculties will occur with respect to the separate diaphagms. Further, this patent does not overcome many of the above-mentioned difficulties of the other prior art.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a constant flow sampling device that will not have sealing problems, that will be balanced with respect to the various sources, that will employ a minimum number of parts to reduce manufacturing costs and maintenance costs, and which will operate entirely satisfactorily.

With the present invention, a single valve block body is employed with a single blind end bore for exhausing all of the material supplied from the various sources and not sampled, a single bore for feeding all of the fluids sampled to a monitor or the like, a plurality of parallel through bores intersecting the common exhaust bore at right angles, a plurality of parallel valve chamber bores perpendicular to and intersecting the common sample bore, and a plurality of parallel sampling bores extending from the respective valve chamber bores to the respective supply bores. Balancing of the various supply lines as to their flow is accomplished by valve body block, which sheet is selectively movable between a position spaced from and a position engaging a plurality of tubes respectively sealingly held within the sample communicating bores and extending into the valve chambers. Valve actuation is obtained by means of a common cam shaft with a plurality of cams respectively pivoting L-shaped levers that will move actuating buttons into and out of engagement with the resilient sheet opposite respective ones of the tubes. The L-shaped actuating levers are pivotally mounted between the opposed legs of respective U-shaped brackets that additionally mount electric switches operable by pivoting of the L-shaped levers for purposes more fully set forth in the above-identified copending patent application.

BRIEF DESCRIPTION OF THE DRAWINGS Further objects, features and advantages of the present invention will become more clear from the following detailed description of the drawing, wherein:

FIG. 1 is a top view of the sampling valve with the systems connections schematically shown;

FIG. 2 is a side elevation view looking from the right of FIG. 1; and

FIG. 3 is a cross-sectional view taken along line 3--3 of FIG. 2, with portions removed.

DETAILED DESCRIPTION OF THE DRAWING As more fully set forth in the above-identified copending application of the present applicant, the valve of the present invention is employed in a system wherein it is desired to continuously draw fluid from a plurality of sources to a control area where sequentially sample fluid from the sources will be monitored to detect a characteristic. For example, the several sources may be different rooms or areas of a building or system of buildings and it is desired to monitor the atmosphere within these areas for the presence of particles or the like that would indicate a tire or impending fire. Since such a monitoring instrument would be quite expensive, the samples are sequentially fed to only one common such instrument.

Most likely, the distance between the central control area and the various areas to be monitored will vary so that the pressure drop in the lines connecting these areas will correspondingly vary, and further the characteristics of normal fluid obtained from these areas may vary so that some compensating means is desirable. For example, the monitoring equipment may make a quantity determination of particles within the samples and one area to be monitored may be an office area normally having a negligible amount of such particles while another area may be a machine and tool area normally having a large quantity of such particles in its atmosphere.

The description of the value of the present invention will be made with the environment of the aboveidentified application as briefly described above as a specific preferred example. However, it is contemplated that the sources may be various liquid lines in a manufacturing facility and the monitoring device may merely sample the liquid to determine if it meets certain chemical standards. Many other such environments for the valve of the present invention are contemplated according to its broader aspects.

As shown in FIG. 1, the valve 1 of the present invention may be situated in a control area remote from a plurality of fluid sources 2, 3, 4, which, for purposes of an example will be separate rooms of a building. Each of the sources 2 5 are respectively connected to the valve 1 by means of fluid conducting source connecting lines 6, 7, 8, and 9. These lines 6 9 may be any conventional type of pipe and due to the adjustment characteristics of the valve, to be described later, this piping may be designed for convenience with little regard being given to balancing the pressure drops as between the lines. Through internal passages of the valve 1, all of the source connecting lines 6, 7, 8, 9 are connected to a single exhaust connecting line 10 that leads to a constantly running fluid pump 11 that will discharge the fluid through line 12 to a suitable location. These internal passages within the valve 1 are fixed, after adjustment, so that they will always be open and there will be a continuous flow of fluid in each of the source connecting lines 6, 7, 8, 9 from the sources to the valve 1 to where the source fluids are combined and continuously pumped through exhaust connecting line 10 and discharge line 12. Selectively and preferably sequentially, samples of the fluid from each of the source connecting lines 6, 7, 8, 9 are taken separately and delivered singly to the monitor connecting line 13 to where they are delivered to a fluid monitor 14. Flow through the monitor connecting line 13 and monitor 14 is maintained by the pump 15, which will draw sample fluid through the monitor connecting'line 13, monitor 14 and line 16 to discharge it through line 17 to a suitable location. Preferably, the monitor 14 is a particle counting device of the character more fully disclosed in applicants copending above-identified application; however, it may be of any other type of device used to determine one or more characteristics of a fluid. Although two pumps 11 and have been shown, additional or only pumps may be provided separately in each of the supply connecting lines 6, 7, 8, 9.

As mentioned above, a constant flow of fluid is maintained from each of the sources 2, 3, 4, 5 through the valve 1 by means of the pump 11 to the discharge line 12. As shown in FIGS. 1 and 3, fluid from source 3 passes to the valve 1 through source connecting line 7 that is threadably coupled to the tapered and threaded inlet port 18 in the valve body or block 19. The inlet port 18 is a part of a straight line fluid passage extend ing entirely through the block 19 and further comprising a connecting bore 20, a restriction 21 and a threaded bore 22. A threaded plug 23, in the nature of a set screw, is screwed into the threaded bore 22 to seal the same. Perpendicular to the bore 22 and in intersecting communication therewith, there extends an exhaust passage bore 24 that is blind at one end 25 and terminates at its other end at a tapered and threaded exhaust port 26, which is threadably connected by suitable means to the exhaust connecting line 10. Thus, fluid will flow from source 3 through source connecting line 7, to inlet port 18, through bore 20, through restriction 21 with a pressure reduction, into bore 22, through bore 24, from outlet port 26 to exhaust connecting line 10 to the pump 11 and finally to the discharge line 12. In a similar manner, fluid from source 2 -will flow through source connecting line 6 to inlet port 27; fluid from source 5 will flow through source connecting line 9 to inlet port 28; and fluid from source 4 will flow through source connecting line 8 to inlet port 29. A cross section taken centrally through each of the inlet ports 27, 28 and 29 parallel with the plane of FIG. 3 would disclose structure identical to that of FIG. 3. Thus, it is seen that flow from source connecting lines 6-9 is continuous through the valve body to the common exhaust bore 24.

For each source, there is an individual diaphragm valve identical to that shown in FIG. 3 and a plurality of passages within the valve block 19 for selectively fluid connecting the bore 20 with a monitor connecting line 13. Since the structure is the same for each of the above-mentioned cross-sections with respect to inlet ports 18, 27, 28, 29, only the structure associated with inlet port 18 will be described in detail in FIG. 3. A valve chamber bore 30 extends from an outer face of the valve block 19 part way toward the bore 20 along a path that would intersect the center line of the bore 20 at right angles. A common sample collecting bore or passage 31 extends parallel to the exhaust bore 24 from a blind end 32 to an open outlet port end 33 that is tapered and threaded for the reception of a coupling to secure the monitor connecting line 13. As seen in FIG. 3, the valve chamber bore 30 and the sample collecting bore 31 intersect so that they are in fluid communication. A sample bore or passage 34 is in alignment with and extends from the valve chamber bore 30 to where it intersects in fluid communication with the bore 20 between the inlet port 18 and the restriction 21.

A diaphragm valve 35 will selectively control the passage of sample fluid from the bore 20 through the sample bore 34 into the valve chamber bore 30, to where it is delivered to the common sample collecting bore 31. The stationary portion of the diaphragm valve is formed by a tube 36 that sealingly extends partially into the sample bore 34 for support at one end and extends freely into the valve chamber bore 30 at its other end. A resilient sheet 37, preferably constructed of neoprene rubber, extends over and sealingly covers all of the four valve chamber bores 30. The resilient sheet 37 is clampingly and sealingly secured to the valve block 19 by means of a rigid plate 38, which is rigidly secured to the valve block 19 by means of fasteners 39 and 40. A coil spring 42 concentrically surrounds the tube 36 to urge the resilient sheet 37 away from the tube 36 and provide fluid communication between the sample bore 34 and the valve chamber bore 30. When the resilient sheet 37 is pressed tightly against the opening of the free end of the tube 36, there will be no fluid communication between the sample bore 34 and the valve chamber bore 30, that is, the valve will be closed.

Valving movement of the resilient sheet 37 will be determined by the position of a separate button 43 having an outer cylindrical portion 44, an annular shoulder 45, and an inner cylindrical portion 46. The inner cylindrical portion 46 extends through an appropriately sized hole in the plate 38 which may be of the same diameter as the valve chamber bore 30. A valve actuating L-shaped lever 47 has one leg provided with a hole slightly larger than and receiving the outer cylindrical portion 44 so as to be able to move the button 43 to the left as seen in FIG. 3 by engagement with the annular shoulder 45 when the lever 47 is pivoted in the counterclockwise direction. Four U-shaped brackets 48 each have opposed legs 49, 50 and a central web portion 51 that is rigidly secured by means of threaded fasteners 52 to the valve block 19. As shown in the partial section of FIG. 2, set screws 53 are driven through the legs 49, 50 so that their conical inner ends are received within correspondingly shaped recesses in the bight portion of the respective L-shaped levers 47 to form the pivotal mounting for the levers. As shown in FIG. 3, an L-shaped spring 54 has one leg in engagement with one leg of its associated L-shaped lever 47 and its other leg rigidly secured to the web portion 51 of the associated bracket by means of the fasteners 52. Thus, the spring 54 will bias the lever 47 in the counterclockwise direction to in turn, through the intermediary of the button 43, force the resilient sheet 37 into sealing engagement with the tube 36 against the counter-acting bias of the weaker spring 42. Thus, the diaphragm valves are normally closed.

A cam and follower arrangement is provided to move the individual valves sequentially into open positions. For this purpose, an electric motor 55 is secured by fasteners 56 to a bracket 57, which bracket is in turn secured to the valve block 19 by means of threaded fasteners 58. The output shaft 59 of the motor drives a spur gear 60, which spur gear 60 is in meshing engagement with a larger spur gear 61 for a speed reduction drive. The spur gear 61 is drivingly secured to a cam shaft 62 having its opposite ends rotatably mounted in the bracket 57 and a bracket 63 secured to the opposite end of the valve block 19 from the bracket 57 by means of fasteners 64. Four cams 65 are drivingly secured to the cam shaft 62. As shown in FIG. 3, the cam 65 will rotate in the counter-clockwise direction to engage a roller 66 of a cam follower 67 that is secured to one leg of the lever 47. Thus, when the high portion 68 of the cam 65 moves around into engagement with the roller 66, the lever 47 will be pivoted in the clockwise direction to allow spring 42 to move the resilient sheet 37 and button 43 out of engagement with the open end of the tube 36 to thus open the diaphragm valve. All of the earns 65 are identical, but they are mounted on the shaft 62 in four different positions, each being 90 rotated from the preceeding one, for example. Thus, the four separate diaphragm valves will be sequentially opened as the shaft 62 continuously rotates in the counter-clockwise direction. Thus, samples of the fluid entering inlet ports 18, 27, 28 and 29 will be sequentially and individually fed to the common sample collecting bore 31 for travel through the monitor connecting line 13 to the monitor 14.

As more fully set forth in the above-identified copending application, a plurality of switches are associated with each diaphragm valve to inform the monitoring equipment which of the samples is being sent. These switches are preferably adjustable microswitches 69 having actuating buttons in contact with the spring 54 or lever 47 so as to be actuated each time the lever 47 rotates in the clockwise direction from the position illustrated in FIG. 3. Further, a fifth cam 70 is drivingly mounted on the shaft 62 for actuating a separate micro-switch 71 to indicate sample switching. Since there are four diaphragm valves, the cam 70 will have four actuating surfaces so that the switch 71 will be actuated four times for each single revolution of the shaft 62. The cam surfaces are equally spaced around the cam 70 and angularly correlated with respect to the relative positioning of the cams 65 so that the switch 71 will be actuated for each transition period, with an overlap if desired, when one diaphragm valve is being closed and another diaphragm valve is being opened so that the monitoring device 14 may be cut out or otherwise controlled when the interface between two fluid samples reaches it. This is desirable, because the interface between two fluid samples cannot be precise as there will be some mixing.

OPERATION When it is desired to measure one or more characteristics of fluid from two or more sources, the sampling valve of the present invention is employed with the circuitry of the above-identified copending application. Source connecting lines 6, 7, 8, 9, are respectively connected to the separate sources of fluid 2, 3, 4, 5, for example different rooms of a building. By means of the fixed open passages within the valve block 19, fluid from the lines 6, 7, 8, 9, is collected, combined in the exhaust passage bore 24 and delivered to line 10 to be exhausted by the pump 1 l for continuous flow from all of the sources.

For sequentially sampling these sources, the motor 55 is operated to continuously rotate the cam shaft 62 and individual cams 65, 70, in the counterclockwise direction, as viewed in FIG. 3. The cams 65 will sequentially pivot the actuating levers 47 inthe clockwise direction to release the force on the respective buttons 43 so that the coil spring 42 associated therewith may move the resilient sheet 37 away from the adjacent opening of the tube 36, which is the open position of the valve. When one of the diaphragm valves 35 is thus opened, some of the sample fluid flowing in bore 20 will move through bore 34, tube 36, between the tube 36 and resilient sheet 37, intothe valve chamber bore 30, through the sample collecting bore 31, and into the monitor connecting line 13 for analysis by the monitor 14. Particularly when pumps are only provided within the source connecting lines 6, 7, 8, 9, the restriction 21 will produce a back pressure aiding in the movement of fluid into the sample bore 34; even with the pump arrangement as shown in FIG. 1, the restriction 21 will produce a higher pressure upstream of the restriction 21 than immediately downstream to assist the pump 15 in drawing sample fluid.

The same clockwise pivoting of the levers 47 that actuates the diaphragm valves 35, will actuate the associated switches 69, two of which are actuated by each lever 47. These switches 69, will transmit signals to the circuitry of applicants copending application to assist the monitor 14 in evaulating the samples as they arrive. Further, the cam will actuate the switch on and off four times for each revolution of the cam shaft 62; this will be timed so that the monitor 14 will be cut out or otherwise signaled each time that there is a transition from fluid obtained from one valve to fluid obtained from the next valve travelling within the sample collecting bore 31 and monitor connecting line 13. Preferably, the earns 65, 70 are mounted on the shaft 62 with set screws or the like so that they may be angularly adjusted for the proper sequence of operating the diaphragm valves 35. Also, the high portion of the cams 65 will determine the duration of valve actuation. Similarly, the position of the cam 70 may be adjusted by a set screw or the like and its actuatingcam surfaces may be correlated to the desired time for cutting out the monitor 14 shortly before and after the transition gas mixture is received and discharged from monitor 14.

A threaded plug 23 is provided for each of the four threaded bores 22, so that the sampling valve may be adjusted to compensate for different pressure drops in the source connecting lines 6, 7, 8, 9 and for different pressure heads produced by the various pumps involved. Movement of the plug 23 further into the threaded bore 22, as viewed in FIG. 3, will further restrict passage of fluid from the bore 22 into the common exhaust passage 24 for the above-mentioned compensating adjustment. Thus, the plugs 23 are used to adjust for the desired flows in the sampling lines and response times.

In precision fluid character measuring systems, it is highly important that leakage be prevented. The use of a single firmly clampd resilient sheet for all of the diaphragm valves 35 completely seals the valve block when taken together with the normally very tight threaded seals for the various line couplings. Further, the calibrations and adjustments provided by the threaded plugs 23 greatly increase the versatility of the instrument as to its usage with materially different sources and as to its location. The compact construction of the cams, valve actuating mechanism and switches not only employs a minimum of manufacturing expense, maintenance cost and room, but it further assures reliable leakage free operation of the sampling valve by being located entirely out of the sealed fluid containing area. That is, there are no moving shafts or the like that move from the sealed to the unsealed area and the number of elements within the sealed area is kept to a minimum. Another advantage is that there is no contamination of sampled fluid by bearing oils, greases or leaks.

Many mofications are contemplated, e.g., coil springs may replace the L-shaped springs for biasing the L- shaped levers. Further, any number of zones or sources may be sampled by adding additional valves, cams, lines, levers, etc.

Further embodiments, variations and modifications are contemplated within the broader aspects of the present invention as defined by the spirit and scope of the following claims.

What is claimed is:

l. A sampling valve to be used in a system wherein selective samples of a fluid are to be taken from separate fluid sources, comprising: a first source passage having an inlet to be connected to a first source of fluid and an outlet; a second source passage having an inlet to be connected to a second source of fluid and an outlet; said source passages being substantially identical; a first sampling passage having an inlet connected to said first source passage between the source passage inlet and outlet, and an outlet to feed a fluid sample; a first slectively operable valve in said fluid sampling passage between the sampling passage inlet and outlet; a second sampling passage between the sampling passage inlet and outlet; a second sampling passage having an inlet connected to said second source passage between the second source passage inlet and outlet, and an outlet to feed a fluid sample; a second selectively operable valve in said second sampling passage between the second sampling passage inlet and outlet; said fluid sampling passages being substantially identical and said valves being substantially identical; and a common sampling passage connected to said sampling passage outlets; manual means for selectively adjusting the fluid resistance in at least one of said source passages to compensate for normal variations in fluid characteristics in the fluid from the sources and to obtain uniform pressures in said common sampling passage with different fluid inlet pressures in each of said source passages; and said manual adjusting means being a screw threaded into and out of said at least one source passage for respectively increasing and decreasing the upstream fluid pressure.

2. A sampling valve to be used in a system wherein selective samples of a fluid are to be taken from separate fluid sources, comprising: a first source passage having an inlet to be connected to a first source of fluid and an outlet; a second source passage having an inlet to be connected to a second source of fluid and an outlet; said source passages being substantially identical; a first sampling passage having an inlet connected to said first source passage between the source passage inlet and outlet, and an outlet to feed a fluid sample; a first selectively operable valve in said fluid sampling passage between the sampling passage inlet and outlet; a second sampling passage having an inlet connected to said second source passage between the second source passage inlet and outlet, and an outlet to feed a fluid sample; a second selectively operable valve in said second sampling passage between the second sampling passage inlet and outlet; said fluid sampling passages being substantially identical and said valves being substantially identical; a common sampling passage connected to said sampling passage outlets; means for adjusting the fluid resistance in at least one of said source pasages to compensate for normal variations in fluid characteristics in the fluid from the sources; said adjusting means being a screw threaded into and out of said at least one source passage; a valve body; said first and second source passages including two respective straight line passages extending parallel to each other and completely through said body, and a common exhaust passage extending into said body at right angles to said straight line passages and at least partially intersecting said straight line passages; said screw being threaded into and sealing one end of said straight line passages to extend into the intersection area of said common exhaust passage and one straight line passage; and the opposite end of said straight line passages having connector means for selectively coupling respective source supply lines.

3. A sampling valve to be used in a system wherein selective samples of a fluid are to be taken from separate fluid sources, comprising: a first source passage having an inlet to be connected to a first source of fluid and an outlet; a second source passage having an inlet to be connected to a second source of fluid and an outlet; a first sampling passage having an inlet connected to said first source passage between the source passage inlet and outlet, and an outlet to feed a fluid sample; a first selectively operable valve in said fluid sampling passage between the sampling passage inlet and outlet; a second sampling passage having an inlet connected to said second source passage between the second source passage inlet and outlet, and an outlet to feed a fluid sample; a second selectively operable valve in said second sampling passage betweeen the second sampling passage inlet and outlet; a common sampling passage connected to said sampling passage outlets; means for adjusting the fluid resistance in at least one of said source passages to compensate for normal variations in fluid characteristics in the fluid from the sources;

means for creating a substantial pressure drop between each of said sampling passage inlets and source passage outlets so that fluid from pressurized sources will prefer to flow into said common sampling passage when its associated valve is open instead of through its source passage outlet; said pressure drop creating means including a fixed, nonadjustable fluid throttling orifice in each of said first and second source passages between their respective outlets and sampling passage inlets.

4. The device of claim 4, wherein said fluid resistance adjusting means includes a metering screw threaded into each of said first and second source passages, to affectively adjust the cross-sectional area of their respective outlets, between their respective orifices and outlets.

5. A sampling valve to be used in a system wherein selective samples of a fluid are to be taken from separate fluid sources, comprising: a first source passage having an inlet to be connected to a first source of fluid and an outlet; a second source passage having an inlet to be connected to a second source of fluid and an outlet; a common exhaust passage being connected to said outlets; a first sampling passage having an inlet connected to said first source passage between the source passage inlet and outlet, and an outlet to feed a fluid sample; a first selectively operable valve in said first fluid sampling passage between the sampling passage inlet and outlet; a second sampling passage having an inlet connected to said second source passage between the second source passage inlet and outlet, and an outlet to feed a fluid sample; a second selectively operable valve in said second sampling passage between the second sampling passage inlet and outlet; and a common sampling passage connected to said sampling passage outlets; said first and second source passages including two respective straight line passages extending parallel to each other; said common exhaust passage extending into said body at right angles to said straight line passages and at least partially intersecting said straight line passages; said sampling passages including two straight line passages intersecting said source straight line passages at right angles respectively; and said common sampling passage extending parallel to said common exhaust passage.

6. The device of claim 5, wherein said sampling straight line passages include respective valve chambers and lines joining said valve chambers and respective ones of said source straight line passages; and said common sampling passage being parallel to said common exhaust passage and intersecting each of said valve chambers.

7. The device of claim 6, including a one piece valve body having therein all of said source, sampling and common passages; wherein said valve chambers are first blind bores extending from one face of said body; said joining lines are parallel bores smaller in diameter and extending from the bottom of respective ones of said valve chamber bores and into respective ones of said source straight line passages; a tubular member sealingly received within each of said joining lines and extending outwardly into respective ones of said valve chamber bores; said valve means including movable valve means selectively movable into sealing engagement with the terminal end of each of said tubular members within respective valve chamber bores.

8. The valve of claim 7, wherein said movable valve means further includes a single resilient sheet sealing all of said valve chamber bores and movable between a first position sealingly engaging said tube members and a second position spaced from said tubes.

9. The device of claim 8, wherein each of said movable valve means further includes a lever pivotally mounted on said valve body, means movable with said lever for engaging said resilient sheet to move said resil ient sheet between its two positions in response to pivoting of said lever, cam follower means on said lever, and a cam rotatable to selectively engage said cam follower means for pivoting said lever; and further including a rotatably driving shaft drivingly carrying all of said cams.

10. The device of claim 9, including a spring means for each of said levers biasing its respective lever in one pivoted direction toward said cams; and electric switch means mounted on said valve body to be actuated by pivotal movement of said levers.

11. The apparatus of claim 9, wherein said levers are L-shaped with two legs; and means for pivotally mounting said levers including a U-shaped bracket for each of said levers, each of said brackets having a web portion connected to said valve body and parallel leg portions on each side of said lever, and bearing tipped set screws threadably received through each of said U- shaped bracket legs and driven into the connection point for said L-shaped bracket legs.

12. The device of claim 11, including a spring means for each of said levers biasing its respective lever in one pivoted direction toward said carns; said spring means being an L-shaped leaf spring having one of its legs engaging one leg' of the respective L-shaped lever and its other leg being secured to the web portion of the respective U-shaped bracket. 1

13. The device of claim 12, including electric switch means mounted on said U-shaped bracket legs.

14. The device of claim 13, including a separate common cam mounted on said shaft for rotation therewith and having a plurality of cam surfaces around its periphery corresponding in number to the number of separate source passages; and a single electric switch mounted on said valve body to be actuated by each cam surface on said common cam.

15. A sampling valve to be used in a system wherein selective samples of a fliud are to be taken from separate fluid sources, comprising: a first source passage having an inlet to be connected to a first source of fluid and an outlet; a second source passage having an inlet to be connected to a second source of fluid and an outlet; a first sampling passage having an inlet connected to said first source passage between the source passage inlet and outlet, and an outlet to feed a fluid sample; a first selectively operable valve in said fluid sampling passage between the sampling passage inlet and outlet; a second sampling passage having an inlet connected to said second source passage between the second source passage inlet and outlet, and an outlet to feed a fluid sample; a second selectively operable valve in said second sampling passage between the second sampling passage inlet and outlet; and a common sampling passage connected to said sampling passage outlets; a base; a shaft rotatably mounted with respect to said base; a plurality of cams drivingly mounted on said shaft and in axially spaced relationship; a corresponding plurality of U-shaped brackets, each having opposed legs extending generally perpendicular to said shaft and a web portion rigidly secured with respect to said base; a corresponding plurality of levers having at one end follower means thereon for engaging respective ones of said cams and at the other end means for actuating respective ones of said valves; a corresponding plurality of set screw pairs, each pair having a set screw threadably engaged with a corresponding leg of the associated U-shaped bracket and opposed conical terminal ends extending inwardly from respective bracket legs and into opposed sides of said lever between its ends along a line spaced from said follower means and actuating means, and parallel with said shaft axis.

16. The device of claim 15, including a corresponding plurality of springs, each being operatively connected to a corresponding one of said levers.

17. The device of claim 15, wherein each of said levers is L-shaped in cross section perpendicular to the axis of said shaft; and separate electrical switch means mounted with respect to said base to be actuated by pivotal movement of one leg of each L-shaped lever.

18. A multiple valve, comprising: a valve block having at least two open ended valve chambers therein; a stationary valve seat in each of said valve chambers; a single resilient sheet extending over and covering all of said valve chambers; means to clamp said resilient sheet to said block for sealing the open ends of said valve chambers and sealing said valve chambers with respect to each other; separate movable valve means on the opposite side of said resilient sheet from each of said valve chambers for independently holding said sheet in tight sealing engagement directly with respective ones of said stationary valve seats in one valve closed position and being movable away from said valve chambers to a second valve open position spaced from said one position; a shaft rotatably mounted with respect to said block; a plurality of cams drivingly mounted on said shaft and in axially spaced relationship; a corresponding plurality of U-shaped brackets, each having opposed legs extending generally perpendicular to said shaft and a web portion rigidly secured with respect to said block; a corresponding plurality of levers having at one end follower means thereon for engaging respective ones of said cams and at the other end said movable valve means for actuating respective ones of the valves; a corresponding plurality of set screw pairs, each pair having a set screw threadably engaged with a corresponding leg of the associated U- shaped bracket and opposed conical terminal ends extending inwardly frOm respective bracket legs and into opposed sides of said lever between its ends along a line spaced from said follower means and movable valve means, and parallel with said shaft axis.

19. Th device of claim 18, including a corresponding plurality of springs, each being operatively connected to a corresponding one of said levers.

20. The device of claim 18, wherein each of said levers is L-shaped in cross section perpendiculr to the axis of said shaft; and separate electrical switch means mounted with respect to said base to be actuated by pivotal movement of one leg of each L-shaped lever. 

1. A sampling valve to be used in a system wherein selective samples of a fluid are to be taken from separate fluid sources, comprising: a first source passage having an inlet to be connected to a first source of fluid and an outlet; a second source passage having an inlet to be connected to a second source of fluid and an outlet; said source passages being substantially identical; a first sampling passage having an inlet connected to said first source passage between the source passage inlet and outlet, and an outlet to feed a fluid sample; a first slectively operable valve in said fluid sampling passage between the sampling passage inlet and outlet; a second sampling passage between the sampling passage inlet and outlet; a second sampling passage having an inlet connected to said second source passage between the second source passage inlet and outlet, and an outlet to feed a fluid sample; a second selectively operable valve in said second sampling passage between the second sampling passage inlet and outlet; said fluid sampling passages being substantially identical and said valves being substantially identical; and a common sampling passage connected to said sampling passage outlets; manual means for selectively adjusting the fluid resistance in at least one of said source passages to compensate for normal variations in fluid characteristics in the fluid from the sources and to obtain uniform pressures in said common sampling passage with different fluid inlet pressures in each of said source passages; and said manual adjusting means being a screw threaded into and out of said at least one source passage for respectively increasing and decreasing the upstream fluid pressure.
 2. A sampling valve to be used in a system wherein selective samples of a fluid are to be taken from separate fluid sources, comprising: a first source passage having an inlet to be connected to a first source of fluid and an outlet; a second source passage having an inlet to be connected to a second source of fluid and an outlet; said source passages being substantially identical; a first sampling passage having an inlet connected to said first source passage between the source passage inlet and outlet, and an outlet to feed a fluid sample; a first selectively operable valve in said fluid sampling passage between the sampling passage inlet and outlet; a second sampling passage having an inlet connected to said second source passage between the second source passage inlet and outlet, and an outlet to feed a fluid sample; a second selectively operable valve in said second sampling passage between the second sampling passage inlet and outlet; said fluid sampling passages being substantially identical and said valves being substantially identical; a common sampling passage connected to said sampling passage outlets; means for adjusting the fluid resistance in at least one of said source pasages to compensate for normal variations in fluid characteristics in the fluid from the sources; said adjusting means being a screw threaded into and out of said at least one source passage; a valve body; said first and second source passages including two respective straight line passages extending parallel to each other and completely through said body, and a common exhaust passage extending into said body at right angles to said straight line passages and at least partially intersecting said straight line passages; said screw being threaded into and sealing one end of said straight line passages to extend into the intersection area of said common exhaust passage and one straight line passage; and the opposite end of said straiGht line passages having connector means for selectively coupling respective source supply lines.
 3. A sampling valve to be used in a system wherein selective samples of a fluid are to be taken from separate fluid sources, comprising: a first source passage having an inlet to be connected to a first source of fluid and an outlet; a second source passage having an inlet to be connected to a second source of fluid and an outlet; a first sampling passage having an inlet connected to said first source passage between the source passage inlet and outlet, and an outlet to feed a fluid sample; a first selectively operable valve in said fluid sampling passage between the sampling passage inlet and outlet; a second sampling passage having an inlet connected to said second source passage between the second source passage inlet and outlet, and an outlet to feed a fluid sample; a second selectively operable valve in said second sampling passage betweeen the second sampling passage inlet and outlet; a common sampling passage connected to said sampling passage outlets; means for adjusting the fluid resistance in at least one of said source passages to compensate for normal variations in fluid characteristics in the fluid from the sources; means for creating a substantial pressure drop between each of said sampling passage inlets and source passage outlets so that fluid from pressurized sources will prefer to flow into said common sampling passage when its associated valve is open instead of through its source passage outlet; said pressure drop creating means including a fixed, nonadjustable fluid throttling orifice in each of said first and second source passages between their respective outlets and sampling passage inlets.
 4. The device of claim 4, wherein said fluid resistance adjusting means includes a metering screw threaded into each of said first and second source passages, to affectively adjust the cross-sectional area of their respective outlets, between their respective orifices and outlets.
 5. A sampling valve to be used in a system wherein selective samples of a fluid are to be taken from separate fluid sources, comprising: a first source passage having an inlet to be connected to a first source of fluid and an outlet; a second source passage having an inlet to be connected to a second source of fluid and an outlet; a common exhaust passage being connected to said outlets; a first sampling passage having an inlet connected to said first source passage between the source passage inlet and outlet, and an outlet to feed a fluid sample; a first selectively operable valve in said first fluid sampling passage between the sampling passage inlet and outlet; a second sampling passage having an inlet connected to said second source passage between the second source passage inlet and outlet, and an outlet to feed a fluid sample; a second selectively operable valve in said second sampling passage between the second sampling passage inlet and outlet; and a common sampling passage connected to said sampling passage outlets; said first and second source passages including two respective straight line passages extending parallel to each other; said common exhaust passage extending into said body at right angles to said straight line passages and at least partially intersecting said straight line passages; said sampling passages including two straight line passages intersecting said source straight line passages at right angles respectively; and said common sampling passage extending parallel to said common exhaust passage.
 6. The device of claim 5, wherein said sampling straight line passages include respective valve chambers and lines joining said valve chambers and respective ones of said source straight line passages; and said common sampling passage being parallel to said common exhaust passage and intersecting each of said valve chambers.
 7. The device of claim 6, including a one piece valve body having therein all of said source, sampling and common passages; wherein said valve cHambers are first blind bores extending from one face of said body; said joining lines are parallel bores smaller in diameter and extending from the bottom of respective ones of said valve chamber bores and into respective ones of said source straight line passages; a tubular member sealingly received within each of said joining lines and extending outwardly into respective ones of said valve chamber bores; said valve means including movable valve means selectively movable into sealing engagement with the terminal end of each of said tubular members within respective valve chamber bores.
 8. The valve of claim 7, wherein said movable valve means further includes a single resilient sheet sealing all of said valve chamber bores and movable between a first position sealingly engaging said tube members and a second position spaced from said tubes.
 9. The device of claim 8, wherein each of said movable valve means further includes a lever pivotally mounted on said valve body, means movable with said lever for engaging said resilient sheet to move said resilient sheet between its two positions in response to pivoting of said lever, cam follower means on said lever, and a cam rotatable to selectively engage said cam follower means for pivoting said lever; and further including a rotatably driving shaft drivingly carrying all of said cams.
 10. The device of claim 9, including a spring means for each of said levers biasing its respective lever in one pivoted direction toward said cams; and electric switch means mounted on said valve body to be actuated by pivotal movement of said levers.
 11. The apparatus of claim 9, wherein said levers are L-shaped with two legs; and means for pivotally mounting said levers including a U-shaped bracket for each of said levers, each of said brackets having a web portion connected to said valve body and parallel leg portions on each side of said lever, and bearing tipped set screws threadably received through each of said U-shaped bracket legs and driven into the connection point for said L-shaped bracket legs.
 12. The device of claim 11, including a spring means for each of said levers biasing its respective lever in one pivoted direction toward said cams; said spring means being an L-shaped leaf spring having one of its legs engaging one leg of the respective L-shaped lever and its other leg being secured to the web portion of the respective U-shaped bracket.
 13. The device of claim 12, including electric switch means mounted on said U-shaped bracket legs.
 14. The device of claim 13, including a separate common cam mounted on said shaft for rotation therewith and having a plurality of cam surfaces around its periphery corresponding in number to the number of separate source passages; and a single electric switch mounted on said valve body to be actuated by each cam surface on said common cam.
 15. A sampling valve to be used in a system wherein selective samples of a fliud are to be taken from separate fluid sources, comprising: a first source passage having an inlet to be connected to a first source of fluid and an outlet; a second source passage having an inlet to be connected to a second source of fluid and an outlet; a first sampling passage having an inlet connected to said first source passage between the source passage inlet and outlet, and an outlet to feed a fluid sample; a first selectively operable valve in said fluid sampling passage between the sampling passage inlet and outlet; a second sampling passage having an inlet connected to said second source passage between the second source passage inlet and outlet, and an outlet to feed a fluid sample; a second selectively operable valve in said second sampling passage between the second sampling passage inlet and outlet; and a common sampling passage connected to said sampling passage outlets; a base; a shaft rotatably mounted with respect to said base; a plurality of cams drivingly mounted on said shaft and in axially spaced relationship; a correspondiNg plurality of U-shaped brackets, each having opposed legs extending generally perpendicular to said shaft and a web portion rigidly secured with respect to said base; a corresponding plurality of levers having at one end follower means thereon for engaging respective ones of said cams and at the other end means for actuating respective ones of said valves; a corresponding plurality of set screw pairs, each pair having a set screw threadably engaged with a corresponding leg of the associated U-shaped bracket and opposed conical terminal ends extending inwardly from respective bracket legs and into opposed sides of said lever between its ends along a line spaced from said follower means and actuating means, and parallel with said shaft axis.
 16. The device of claim 15, including a corresponding plurality of springs, each being operatively connected to a corresponding one of said levers.
 17. The device of claim 15, wherein each of said levers is L-shaped in cross section perpendicular to the axis of said shaft; and separate electrical switch means mounted with respect to said base to be actuated by pivotal movement of one leg of each L-shaped lever.
 18. A multiple valve, comprising: a valve block having at least two open ended valve chambers therein; a stationary valve seat in each of said valve chambers; a single resilient sheet extending over and covering all of said valve chambers; means to clamp said resilient sheet to said block for sealing the open ends of said valve chambers and sealing said valve chambers with respect to each other; separate movable valve means on the opposite side of said resilient sheet from each of said valve chambers for independently holding said sheet in tight sealing engagement directly with respective ones of said stationary valve seats in one valve closed position and being movable away from said valve chambers to a second valve open position spaced from said one position; a shaft rotatably mounted with respect to said block; a plurality of cams drivingly mounted on said shaft and in axially spaced relationship; a corresponding plurality of U-shaped brackets, each having opposed legs extending generally perpendicular to said shaft and a web portion rigidly secured with respect to said block; a corresponding plurality of levers having at one end follower means thereon for engaging respective ones of said cams and at the other end said movable valve means for actuating respective ones of the valves; a corresponding plurality of set screw pairs, each pair having a set screw threadably engaged with a corresponding leg of the associated U-shaped bracket and opposed conical terminal ends extending inwardly frOm respective bracket legs and into opposed sides of said lever between its ends along a line spaced from said follower means and movable valve means, and parallel with said shaft axis.
 19. Th device of claim 18, including a corresponding plurality of springs, each being operatively connected to a corresponding one of said levers.
 20. The device of claim 18, wherein each of said levers is L-shaped in cross section perpendiculr to the axis of said shaft; and separate electrical switch means mounted with respect to said base to be actuated by pivotal movement of one leg of each L-shaped lever. 